Our sensors are located in the best situations we have in our garden at the old school. They are listed below with information about the situation, calibration and history.

We submit data to the Citizens Weather Observer Programme and therefore comparison of data between local METAR and other stations is available to compare accuracy.



Temp and Humidity

These sensors are located on the Davis ISS, mounted on a 4inch square post, at 1.5m above the lawn. There is a daytime FARS unit fitted to circulate the air when solar energy falls on the solar panel.

Rainfall

A Tipping Bucket raingauge is located on the ISS, at 1.5m above the lawn. There is an option to locate this at the same site as the old raingauge which was located by the Environment Agency, however measurements have shown that this location is better as the height increases the overall area as it is above the fence line. The TBR has been calibrated in accordance to WMO settings. Picture shows the check gauge used to calibrate and check the TBR results are within tolerance.

Wind Speed and Direction

Located on the ISS Post at the moment however will be deployed at a higher location when practical. I am not able to use at the WMO height of 10m due to planning restrictions.

Even at a lower height at Ottery, the measurements have been representative when compared with the local METAR and other local stations.

Solar and UV


These are mounted on a sensor shelf, on the ISS and are located in the garden so suffers from a slight enclosing.

Leaf Wetness

This is a Hobby Boards 1-wire sensor, located on the post at 1m high. This sensor has been calibrated using a plant sprayer and some mathematics !! The Leaf Wetness sensor also provides a very good indicator for the presence of light showers.

In this case, a light shower which was less than a 0.2mm tip of the TBR, but is still displayed as happening. The high temperature shows the moisture being evaporated quite quickly.


Soil Temperature

Using Dallas Maxim DS18S20 sensors at 5cm and 30cm below the surface, located in a 10mm conduit pipe. This conduit also contains the Grass Temp Sensor at 5cm above the surface.

Lightning

As a lightning node for the Blitzortung network, a crossed loop antenna at 0.71m square is used. This is made from 20mm electrical conduit, containing 8 turns of 1.5mm2 copper wire.



The preamplifier circuit is housed in the IP rated box at the bottom of the antenna with an STP connection back to the Evaluation board which runs an ATMEGA processor, providing output to a RS232 connection. Client software sends data to a chentral server in Germany.

The pre-amp still requires to settle, with some trim adjustment to be carried out to lower the false strike rejection rate.

Background Radiation

GM-10 Serial from Blackcatsystems, Westminster, ML, USA.

Using a BAFO 816 USB to dual RS232 connected to a Ubuntu 64bit virtual machine, running a modified version of GM4LIN. Data is recorded every 10 seconds and submitted to a mySQL database. A daily cronjob averages the daily records and updates a new table with the data.